Free Electrical Calculators & Tools
Quick electrical calculators to get the right wire size, check voltage drop, and calculate loads. Built by an electrician, for electricians.
Construction Bid & Estimate Planner
Professional spreadsheet template for contractors, electricians, and plumbers. Create accurate bids and win more projects with automated formulas, customizable templates, and dynamic color coding.
Why Use ElectricianCalc.com?
NEC Compliant
All calculations follow National Electrical Code standards and industry best practices for safe electrical installations.
Instant Results
Real-time electrical calculations with immediate feedback and comprehensive analysis for all your projects.
Mobile Ready
Responsive design works perfectly on phones, tablets, and desktop computers for on-the-job calculations.
Always Free
Free electrical tools available at no cost for electricians, engineers, and contractors.
Common Electrical Installation Challenges
Wire Size Selection
Choosing the wrong wire size is expensive and dangerous. Our wire sizing calculator considers load current, distance, voltage drop limits, and temperature conditions to help you pick the right gauge every time. Saves money on materials and prevents code violations.
Load Calculations
Getting accurate load calculations is critical for sizing panels, breakers, and feeders. Our calculators handle residential, commercial, and industrial loads according to NEC requirements. Perfect for permit applications and electrical inspections.
Voltage Drop Issues
Long wire runs can cause voltage drop problems that affect equipment performance. Our voltage drop calculator helps you find out if your installation meets NEC 3% and 5% limits, preventing motor burnout and lighting issues.
Frequently Asked Questions
Are these calculators accurate enough for real jobs?
Yes, we use the same formulas that electricians use. The wire sizing and voltage drop calculations follow NEC standards exactly. Many electricians use these daily for actual installations.
Why do I get different results than other calculators?
Some calculators use simplified formulas or don't account for temperature correction factors. Our calculators include all the variables that affect real installations, which gives more accurate results.
Can I use these for my electrical license exam?
These are great for practice and understanding concepts, but check your exam rules first. Most exams require you to do calculations manually to show you understand the formulas.
Do these work for 240V and 480V systems?
Yes, all voltage levels are supported. Just enter your actual voltage - whether it's 120V, 240V, 480V, or any other value. The calculations automatically adjust for single-phase and three-phase systems.
What if my local electrical code is different?
Our calculators use NEC standards as the baseline, but you can adjust the inputs for local requirements. For example, if your area requires lower voltage drop limits, just use those values instead.
How do I know which wire type to select?
THHN is most common for dry locations, THWN for wet areas. The wire sizing calculator shows different wire types and their temperature ratings to help you pick the right one for your installation.
